CVE-2024-21412 is a vulnerability classified under CWE-693 (Protection Mechanism Failure) affecting Microsoft Windows 11 version 21H2 (build 10.0.0). The issue pertains to the handling of Internet Shortcut files (.url), where a security feature designed to protect users from malicious shortcuts can be bypassed. This bypass allows attackers to craft malicious shortcut files that, when opened by a user, can lead to unauthorized disclosure or modification of sensitive information, compromising confidentiality and integrity. The vulnerability requires no privileges but does require user interaction, such as opening or clicking on a malicious shortcut. The CVSS 3.1 base score is 8.1 (high), with vector AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C, indicating network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, high confidentiality and integrity impact, no availability impact, functional exploit code exists, official fix planned, and confirmed report. No known exploits in the wild have been reported yet. The vulnerability arises from a failure in the protection mechanism that should prevent malicious shortcut files from executing harmful actions or leaking information. This flaw can be leveraged in phishing campaigns or targeted attacks to compromise systems running the affected Windows version.

For European organizations, this vulnerability poses a significant risk due to the widespread adoption of Windows 11 version 21H2 in enterprise and government environments. Successful exploitation could lead to unauthorized access to sensitive data, intellectual property theft, or manipulation of critical information, impacting confidentiality and integrity. Sectors such as finance, healthcare, energy, and government agencies are particularly vulnerable due to the sensitivity of their data and the strategic importance of their operations. The requirement for user interaction means social engineering or phishing tactics could be used to trigger the exploit, increasing the risk in environments with less mature security awareness programs. Although availability is not impacted, the breach of confidentiality and integrity could lead to regulatory penalties under GDPR and damage organizational reputation. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as exploit code may emerge following public disclosure.

1. Apply official Microsoft patches promptly once released to address CVE-2024-21412. 2. Implement strict email and web filtering to block or quarantine suspicious Internet Shortcut files and attachments. 3. Educate users on the risks of interacting with unsolicited or unexpected shortcut files, emphasizing caution with email links and downloads. 4. Use application control policies to restrict execution of Internet Shortcut files from untrusted locations or users. 5. Employ endpoint detection and response (EDR) solutions to monitor and alert on suspicious shortcut file activity or related behaviors. 6. Regularly audit and update security policies to minimize user privileges and reduce attack surface. 7. Consider disabling the handling of Internet Shortcut files in environments where they are not required. 8. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.